Tuesday, June 12, 2018

Elegance is the fuzziest aspect of beauty

Elegance is the fuzziest aspect of beauty. It is often described as an element of surprise, the “aha-effect,” or the discovery of unexpected connections. One specific aspect of elegance is a theory’s resistance to change, often referred to as “rigidity” or (misleadingly, I think) as the ability of a theory to “explain itself.”

By no way do I mean to propose this as a definition of beauty; it is merely a summary of what physicists mean when they say a theory is beautiful. General relativity, string theory, grand unification, and supersymmetry score high on all three aspects of beauty. The standard model, modified gravity, or asymptotically safe gravity, not so much.

But while physicists largely agree on what they mean by beauty, in some cases they disagree on whether a theory fulfills the requirements. This is the case most prominently for quantum mechanics and the multiverse.

I do not agree that grand unification and supersymmetry are beautiful. They require 100s of new parameters and particles in the theory, over the standard model's 20 or so.

A comment says:

A beautiful equation is also one that exhibits the fewest free parameters while explaining the most physics. That's why general relativity is beautiful while the Lagrangian of the Standard Model is ugly as hell. They both work, one by itself and the other by brute force, although I would never compare one with the other.

No, I disagree. This is like saying that the periodic table of the chemical elements is ugly as hell, because it have 92+ elements and some irregularities. It was vastly simpler than any other categorization of the 1000s of known substances, and put them into simple patterns.

The standard model is just quarks, electrons, and neutrinos, with some flavors, generations, colors, and anti-particles, and some bosons for transmitting forces.

2 comments:

Roger,you say "The standard model is just quarks, electrons, and neutrinos, with some flavors, generations, colors, and anti-particles, and some bosons for transmitting forces. "

....and football is a game where you just carry a ball. Oversimplify much?

The standard model also contains no gravity, the universe we happen to live in quite evidently does. Using a one mass theory like general relativity to explain gravity is like using an incomplete model of a single grain of sand in a vacuum to describe a beach, much less a planet or universe. When general relativity can model AT LEAST two masses interacting in the same spacetime, get back to me and I'll eat crow. Until then, it's all just rent seeking.